國家理論科學研究中心學術演講
NCTS Seminar on Scientific Computation

　

           

  Speaker  :        Professor Huaxiong Huang

                          (York University) 
              

  Time        :       Nov. 12 (Friday) AM 10:30 - 12:00

  

  Topic      :        Thermal Stress Reduction in Cz Crystals via Optimal Control

　

  Abstract  :

    Czochralski (Cz) technique is the most popular method for growing single

    crystal. A common problem is that defects (dislocations) start to appear

    when the diameter exceeds critical values, caused by thermal stress.

    Therefore, it is desirable to find optimal growth conditions that minimize

    the stress.

    In this talk, we describe a hybrid of asymptotic and numerical methods for

    computing the thermal stress inside a Cz crystal. Under suitable assumptions,

    we obtain a simple semi-analytical formulation for the von Mise stress. An

    optimal control approach is then used to find growth conditions that reduce

    the thermal stress.

    This is joint work with S. Liang, I. Frigaard and S. Bohun.

                 

  Place     :  

Lecture Room A,

National Center for Theoretical Sciences

4th Floor, The 3rd General Building,

National TsingHua University